1. Field of the Invention
The present invention relates to semiconductor packages and fabrication methods thereof, and more particularly, to a semiconductor package and a fabrication method thereof applicable to package on package (PoP) structures.
2. Description of Related Art
In recent years, to meet the miniaturization requirement of electronic products, PoP type packages have become an R&D focus since they facilitate to save planar area of substrates while maintaining good processing performances.
FIG. 1 is a schematic cross-sectional view of a conventional PoP type package. Referring to FIG. 1, a plurality of solder balls 11 are provided to serve as an interconnection structure for electrically connecting a lower packaging substrate 12 and an upper packaging substrate 13. However, as the I/O density of the package increases, if the size of the package does not change, the pitch between the solder balls 11 must be reduced. As such, solder bridging easily occurs between the solder balls 11.
Therefore, there is a need to provide a semiconductor package and a fabrication method thereof so as to overcome the above-described drawbacks.